The present invention relates to a new and improved construction of a rolling device or roller mill having a controlled-deflection roll possessing a stationary roll support or carrier which is mounted in a frame of the roller mill, there also being provided a substantially tubular roll shell which is rotatable around the roll support and which bears thereon by way of at least one bearing or support element, with the roll shell having at its ends guide members which are rotatably mounted in the roll shell and guided on the roll support in the direction of the pressing or contact or disengaging or lift-off movement respectively, of the roll shell.
Controlled-deflection rolls of this type -- also referred to sometimes in the art as a roll with bending compensation -- are known, for instance, from U.S. Pat. Nos. 3,802,044 and 3,885,283 corresponding to Swiss Pat. Nos. 556,946 and 571,904 respectively. With controlled-deflection rolls of this type, it is possible to compensate for deflection or bending in the roller mill where the rolls cooperate with a backing roll or counter-roll. It is even possible to carry out a desired adjustment of the course of the roll deflection or bending, i.e., the pressing or contact force. Controlled-deflection rolls are therefore increasingly used, for instance, in papermaking machines and in textile processing.
For certain fields of application, for instance in papermaking machines, the controlled-deflection roll must be provided with a scraper device having a scraper blade which scrapes clean the outer surface of the roll shell. This operation helps, for instance, a rolled web to become disengaged from the roll shell or to clean the surface thereof. The scraper blade is accurately adjusted to the outer surface of the roll shell, and the roll surface must be of very high quality, whether it be formed of metal or, for instance, rubber.
Oftentimes, it is also required that the contact or pressing roll, in other words, which ever roll of the pair applies the contact or pressing force, be disengageable from the backing roll so that the roller mill can be opened. In the case of the heretofore known solid rolls possessing an external contact or pressing mechanism, it is common practice for the scraper device to be secured to the roll levers and moved together with the roll.
However, when a controlled-deflection roll of the type referred to is required to be used as a pressing or contact roll, the positioning of the scraper device leads to difficulties, since it can not be mounted in the same manner as it can on solid rolls and the roll support or carrier does not move together with the roll shell.